Poster Presentation

Exploring the Earliest Stage of Star Formation by Modeling the First Hydrostatic Cores

Author(s): Hao-Yuan Duan (NTHU), Shih-Ping Lai (NTHU)

Presenter: Hao-Yuan Duan (NTHU)

Probing the collapse process from a prestellar core to a Class 0 protostar is a key to understand the earliest stage of low-mass star formation.
Theories proposed that a First Hydrostatic Core (FHC) is the representative product at this stage, which has a size of $\sim$ 5 AU, a mass of $\sim$ 0.05 $\msun$, and temperature between 100 -- 200K.
However, FHCs are difficult to observe because they are small, compact, embedded, and short lived.
Several FHC candidates have been proposed, and they are characterized by very cold SEDs with temperature ranging from $\sim$ 10 -- 30K, very low luminosities (< 0.1 -- 0.25 $\lsun$), and most of them are found to have slow, poorly-collimated outflows.
We have explored the physical properties of two FHC candidates, B1-bN \& B1-bS, by fitting all available single dish and interferometric data with a simple model that contains a single hot compact first core-like component at the center surrounded by a large-scale, cold and dusty envelope.
Our results can provide better assessment on whether their physical properties agree with the theoretical expectations of FHCs.